The invention relates to portable radiation detectors and more particularly to portable radiation detectors utilizing a CdTe crystal in a conventional digital wristwatch housing.
In a continuing search for better ways to measure real time exposures to radiation received by workers in the nuclear industry, the wristwatch dosimeter of the invention was developed. It utilizes a CdTe detector similar to that disclosed in U.S. Pat. No. 4,197,461 issued Apr. 8, 1980 to Umbarger et al. and a low-battery power computer to process data. In accordance with the invention, this results in a tiny new instrument capable of sounding an alarm when a dangerous radiation field exists by measuring the radiation field either in a timer/scaler mode or as a ratemeter and alarming when the background increases suddenly or total exposure exceeds a set amount. When not in use as a radiation instrument, it can function as a digital watch. The instrument resembles a digital watch in form which is advantageous. A person normally puts on his or her watch in the morning and does not take it off until he or she goes to bed at night. The instrument can therefore be worn during waking hours other than on the job hours because it both functions as and looks like a conventional digital watch. This makes it easier than previously possible for workers in the nuclear industry to carry an accurate and sophisticated yet simple to operate radiation measuring instrument at any time they are in a potentially hazardous location. The instrument thereby insures less oportunity for serious exposures to occur by timely measurement and warning of dangerous radiation levels.